Officials say the pipeline on the Iranian side of the border has been completed, and that this month will see the start of work on the project in Pakistan.

On Wednesday, the US warned Pakistan to "avoid any sanctionable activity" in connection with the project.

"We think that we provide and are providing the Pakistani government and people a better way to meet their energy needs," State Department spokesman Patrick Ventrell told reporters on Wednesday.

Last year Pakistani Foreign Minister Hina Rabbani Khar insisted the pipeline was "in Pakistan's national interest and will be pursued and completed irrespective of any extraneous considerations".

Power shortages have become a major issue in Pakistan, with the government ordering an investigation into a nation-wide power cut on Sunday blamed on a technical fault in a plant in south-western Balochistan province.